function get_attribute_name(){

	if(document.all) {
    	return "className";
	} else {
		return "class";
	}
}


function tabs(strSection){
	
	document.getElementById("info").style.display = "none";
	document.getElementById("screenshot").style.display = "none";
	document.getElementById("requirements").style.display = "none";

    
	document.getElementById("info_btn").setAttribute(get_attribute_name(), "tab_off");
    document.getElementById("screenshot_btn").setAttribute(get_attribute_name(), "tab_off");
    document.getElementById("requirements_btn").setAttribute(get_attribute_name(), "tab_off");
	
	//turn the selected one on
    document.getElementById(strSection).style.display = "block";
    document.getElementById(strSection + "_btn").setAttribute(get_attribute_name(), "tab_on");
}